This invention pertains to dry fog latex paints and particularly to sprayable latex paints applied by conventional or airless spray equipment where dry fog overspray settles as dust which can be easily cleaned up.
The term "dry fog" is often used to describe a spray applied coating where overspray dries to a tack free non-adherent dust or powder at a free fall distance of at least about eight feet to the clean-up surface. A dry fog coating quite often is used to coat ceiling and similar overhead substrates in commercial environments and especially in commercial or production facilities where dry fog overspray can be easily removed from the surroundings such as from floor or machinery by vacuuming or sweeping. A latex dry fog is a coating designed for high production spray application to ceilings of large commercial buildings. Dry fog requirements dictate that any overspray dry to a tack-free dust in a given free fall permitting quick and easy clean up. Latex paint systems are particularly desirable for such dry fog industrial coating applications although conventional prior art latex coatings do not exhibit satisfactory dry fog characteristics.
It now has been found that a highly desirable dry fog latex paint, preferably an eggshell enamel, can be produced utilizing plastic pigment or high Tg opaque polymer or similar non-film-forming polymer particle at the ambient room temperature of spray application to provide a highly desirable latex paint coating with highly advantageous dry fog overspray properties. In particular, it was advantageously found that solid, hollow or vesiculated plastic particles contained within the latex paint provides a unique latex dry fog paint which enables the latex paint to be applied by conventional or airless spray equipment. The spraying process incorporating the latex paint of this invention advantageously allows the overspray fog to settle as dry dust and permit easy clean up. In the case of an eggshell dry fog latex enamel, it was found that good "dry fog" properties are a function of high volume solids and high PVC. In a plastic pigmented paint system, increasing the PVC while maintaining gloss properties within the limitations specified for an eggshell enamel was achieved at 60-80% PVC. These paint systems also exhibited good adhesion properties and high hiding at reduced TiO.sub.2 levels. Most importantly, their dry fog properties are significantly better than those of a conventionally pigmented latex eggshell enamel. These and other advantages of this invention will become more apparent by referring to the detailed description and illustrative examples.
Prior art patents based on plastic pigment include U.S. Pat. No. 4,069,186, U.S. Pat. No. 4,277,385 and U.S. Pat. No. 4,283,320.